In recent years, there has emerged a hybrid vehicle having both an internal combustion engine and a motor generator mounted thereon in order to reduce a fuel consumption amount of a vehicle. The hybrid vehicle identifies a cylinder based on a crank angle and a cam angle, and injects and ignites fuel at an appropriate timing based on the identification information on the cylinder so as to rotate the internal combustion engine and output torque. Thus, a crank angle sensor is mounted on a crankshaft of the internal combustion engine to detect an angle of the crankshaft.
Also, the motor generator causes an alternating current to flow in accordance with a difference in angle between a stator and a rotor so as to rotate the rotor and output torque. Thus, an angle sensor is mounted on the rotor to detect an angle of the rotor with respect to the stator.
It is necessary to detect the crank angle in order to rotate the internal combustion engine, so that when the crank angle sensor has failed, the internal combustion engine cannot be rotated. Meanwhile, it is necessary to have a rotor angle sensor in order to rotate the motor generator, so that when the rotor angle sensor has failed, the motor generator cannot be rotated.
In view of the above, there is proposed a control device for a hybrid vehicle, including means for calculating a phase difference between the crank angle and the rotor angle when the number of revolutions of the engine is equal to or larger than a set value, the control device being configured to: calculate a pseudo crank angle using a phase difference between a first resolver configured to detect a crank angle and a second resolver configured to detect a rotor angle in preparation for a case in which the first resolver has failed; and calculate a pseudo rotor angle using the crank angle and the phase difference in preparation for a case in which the second resolver has failed, to thereby enable rotation of the internal combustion engine and the motor generator (e.g., refer to Patent Literature 1).